Locomotive control



' Jan. 3, 1928. 1,655,037

E. F. w. ALEXANDERSON LOCOMOTIVE CONTROL Original Filed May 25, 1925 2 Sheets-Sheet 1 Fig. I

Jan. 3, 1928.

1,655,037 E. w. ALEXANDERSON LOCOMOTIVE CONTROL Original Filed May 25, 1925 '2 Sheets-Sheet 2 Fig. 2

Patented Jan. 3, 1928.

UNITED STATES *PATENT OFFICE.

ERNST F. W. ALEXANDERSON, OF SCHENECTADY, NEW YORK, 'ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION" OF NEW YORK.

Looomorrvn ooN'rnoL.

Application filed May 25, 1925, Serial No. 32,543. Renewed May 31, 1827.

My invention relates to control systems, and has for its principal object the provision of an improved system for controlling the power interchanged between an alternating current system and the motive apparatus of an electric-locomotive both while motoring and during regeneration.

Various arrangements have been proposed and used in the 'ast for controlling the power interchanged between a power system and the motive apparatus of an electric locomotive. In the operation ofthese arrangements, it is customary to vary the electrical conditions of the motive apparatus by means of switching devices, the contacts of Which are likely to deteriorate due to the arcing and mechanical Wear incident to their engagement and disengagement. In accordance with my invention, this difliculty is obviated and smooth acceleration and deceleration of the motive apparatus are effected by variation in the grid potential of an electron discharge device interposed between the power system and locomotive.

My invention will be better understood from the following description when considered in connection with the accompanying drawing and its scope will be pointed out in the a pended claims.

Re erring to the drawing, Fig. 1 shows a system wherein my invention has been embodied; and Fig. 2 shows a similar system comprising a modified form of electron discharge device for controlling the power interchanged between the power system and motive apparatus.

Fig. 1 shows a plurality of electric machines 1,2, 3 and 4 arranged to have their respective armature circuits 5, 6, 7 and 8 in terconnected with a power system, shown as a trolley line 9, through means comprising a contact device 10, transformer 11, an electron discharge device shown as a mercury rectifier 12, reactor 13 which is provided for the 45 purpose of smoothing outcurrent pulsations in the armature circuits," and reversing I switch 14 which is adapted {to reverse the connections-of the two groups'of armature circuits, to the vapor electric device 12. The field circuits 15, 16, 17 and 18 of the machines 1, 2, 3 and 4 respectively are connected to the line 9, through reactor 19, electron discharge device 20and transformer 21, the primary circuit of this transformer being shown as connected in series with the 5: primary circuit of the maintransformer 11 and therefore in series relation with the electron discharge device 12, and a switch 22 being provided for connecting the primary circuit of the transformer 21 across a part cc of the primary circuit of the main transformer 11 or in shunt relation to the device 12 during regeneration. The machine field and armature circuits are thus connected in series relation during motoring and in shunt ea relation during regeneration. A switch 23 and source of current 24 are provided for initiating operation of the device 20.

It willbe observed that a iswitch 25 and source of current 26 are provided for ini- 7 tiating operation of the device 12; that anodes 27 to 30 of this device are connected to the terminals of secondary circuits. 31 and 32 of the main transformer 11; that the midpoints of these secondary circuits are connected to the cathode 30' of device 12 through switch 14, armature windings'7 and 8 and armature wi dings 5 and 6 respec tively, and reactor 1 and that grids 33 to 36 of device 12 are connected through curso rent limiting resistors 37 to 40 and a transformer 41 to a hase control device of well known form w ich comprises a polyphase stator winding 43 and a single phase winding 44, mounted on a rotor core 45. stator winding 43' is connected to the line 9 through contact device 10 and to ground through reactor 46 and condenser 47 which are rovided for producing a rotating field in tie core member of the phase shifting device. It will be ap arent that any other suitable means of pro ucing a rotating field in the core members of the phase control device may be utilized.

Condensers 48 and 49 are connected to the terminals of the secondary circuits 31 and 32 respectively in order to ensure stable opera-- tion of the electron dischar e device 12 during slight interruptions o the circuit between the line 9 and contact device 10. A

control lever 50 is mounted on the shaft of the phase control device 42 to facilitate variatign '(in the potential of thegrids 33,v 34, 35

an 3 a Assuming the control lever 50 tube in a positionto cause opposed voltages to be imressed on the grid and anode circuits of the I evice 12, switch 22 to be open, switch 14 to The 83 be closed in its right hand position and op eration of the devices 12 an to have been initiated by means of switches 23 and 25, 1t will be readily understood that the field windings 15 to 18 will be excited but no current will be transmitted to the armature circuits 5 to 8 for the reason that the grid voltages of device 12 are opposed tothe anode volta es of this device. The machines 1 to 4: will t erefore be stationary.

In order to accelerate the machines, the

- lever 56 is operated in a manner to decrease the phase difference between the grid and anode voltages, thus gradually raising the are in phase. It wil operating the lever 50 in a manner to in crease the phase difierence between anode and grid voltages of device 12, the circuit through this device bein these voltages are broug t into phase opposition.

If it is desired to cause the machines l to 4 to supply power tothe line 9 while driven y the momentum of the locomotive, the switch 14 is operated in a manner to reverse the connections between the armature circuits 5 to 8 and device 12, the switch 22 is closed and the lever 50 is operated as before to decrease the phase difference between the anode and id voltages of device 12. The switch 22 t us makes it possible to operate the machines 1 to 4 with series characteristics while motoring and with shunt characteristics while regenerating. This methd of operation is of advantage in that considerable fluctuations in load arelikely to occur during regeneration.

Fig. 2 shows a system which differs from that just described in that the field and armature currents of machines 1- to tare rectifiedflby a single device 12' provided with field anodes 51 and 52 which may be utilized both to rectify the machine field currents and to excite the device 12 in cases where the field circuits are energized continuously. The use of theseparate secondar circuits 31 and 32 is of advantage in that t eir leakage reactance tends'to produce a proper division of load between the two groups of motors.

The embodiments of the invention illustrated and descri ed he ein ha e ee ainterrupted when 1 relation with said I therefore aim to f-covcr by the appended claims all modifications within the true spirit and scope of my invention.

VVhat- 1 claim as new and desire to secure by Letters lPatent ofthe Unit-ed States, is:

1. The combination of an electric machine comprising field and armature circuits, a power line, an electron discharge device connected between said machine and line and provided with grids for controllingthe voltage at which current is transmitted to from said machine, means for varying the grid potential of said device, field control means connected to said line in series relation with said device, and means for connecting said field control means in shunt relation to said device while said machine is operated to supply current to said line.

2. The combination of an electric machine comprising field and armature circuits, a power line, an electron discharge device connected between said machine and line and provided with grids for controlling the voltage at which current is transmitted to and from said machine, phase control means conneoted to said grid for varying the phase of the voltage means arranged to be connected to said line in series relation with said device while said machine is motoring, and means for connecting said field control means to said line in shunt relation to said device while said machine is generating.

3. The combination of a power circuit, an electric locomotive comprising motive apparatus having field and armature circuits, a vapor electric device connected between said line and said armature circuit and provided .with grids for controlling the voltage at which current is transmitted to and from said armature c1rcu1t, field control means arranged to be connected to said power cir- -'cuit in series relation with said device for controlling the energization of said field circuit while said locomotive is driven by said apparatus, and. means for connecting said field control means to said line in shunt relation with said device while said appalocomotive.

4. The method of operating an electric locomotive comprising motive apparatus havmg field and armature circuits connected to a power circuit through an electron discharge device provided with anodes and grids for controlling the voltage at which current is transmitted to and from said a paratus, which consists in connecting said eld circuit to' said wer circuit in series evioe, decreasing the applied thereto, field control 'ratus is driven by the momentum of said phase difierence between the potentials of said anodes and grids to accelerate said apparatus, increasing said phase difference to decelerate said apparatus and interrupt the circuit between said armature and power circuits, connecting said field circuit to said power circuit in shunt relation to said device while said apparatus is driven by the momentum of said locomotive, and varying said phase difference to control the speed at which said apparatus is driven by the momentum of said locomotive.

5. The combination of an electric machine comprising field and armature circuits, a power line, an electron discharge device connected between said machine and line and provided with grids for controlling the voltage at which current is transmitted to and from said machine, mean-s for varying the grid potential of said device, field control means connected to said line in series relation with said device, means for connecting said field control means in shunt relation to said device while said machine is operated to supply current to said'line, and means for maintaining the operation of said device during momentary interruptions in the connection between'said line and said device;

6. The combination of an electric machine comprising field and armature circuits, a

power line, anelectron discharge device con-' terruptions in the connection between said line and said device. 7

7. The combination of a power line, a transformer comprising a primary circuit connected to said line and a plurality of secondary circuits inductively related to said primary circuit, a plurality of groups of electric machines, and an electron discharge device arranged to connect each of said groups to a different one of said secondary circuits and provided with grids for controlling the voltage at which current is transmitted between said groups and said secondary circuits.

8. The combination of a power line, a transformer comprising a primary circuit connected to said line and a plurality of secondary circuits inductively related to said primary circuit, a pluralit of electric machines, and an electron disc arge device provided with grids for controllin the voltage at which current is transmitted etween said machines and said secondary circuits and arranged to connect some of said machines to one of said secondar circuits and other of said machines to otlier of said secondary circuits. I

9. The combination of a power line, a transformer comprising a primary circuit connected to said line and a plurality of secondary circuits inductively related to said primary circuit, a plurality of electric machines, electron dischar e means provided with grids for controlling the voltage at which current is transmitted between said machines and said secondary circuits and arranged to connect some of said machines to one of said secondary circuits and other of said machines to other of said secondary circuits, and phase controlmeans for varying the potential of said rids. In witness whereof, I ave my hand this 23d day of May 1925.

ERNST F. W. ALEXANDERSON,

hereunto set 

